Using collection methods on a Varray

DECLARE      
     
TYPE num_collection IS VARRAY(10) OF NUMBER;      
nums num_collection := num_collection();      
cnt PLS_INTEGER;  
     
BEGIN      
  
nums.EXTEND(nums.LIMIT);  
nums(nums.FIRST) := 10;  
  
FOR idx IN 2..nums.COUNT  
LOOP  
    nums(idx) := nums(idx-1) + 10;  
END LOOP;  
  
FOR idx IN 1..nums.COUNT LOOP      
  DBMS_OUTPUT.put_line('Element '||idx||': '||nums(idx));      
END LOOP;      
    
DBMS_OUTPUT.put_line('Count of elements initially: '||nums.COUNT);     
nums.TRIM;     
DBMS_OUTPUT.put_line('Count of elements after triming: '||nums.COUNT);     
nums.TRIM(2);     
DBMS_OUTPUT.put_line('Count of elements after bulk triming 2 elements: '||nums.COUNT);     
nums.DELETE;      
DBMS_OUTPUT.put_line('Count of elements after delete are: '||nums.COUNT);      
     
END;